Production from offshore wells was originally exported ashore by subsea pipeline, which requires a very large capital expenditure. More recently there has been a move to exploiting more marginal fields by the use of a floating production platform in conjunction with a floating storage facility from which oil is exported periodically by tanker. Commonly, the floating storage facility has been provided by conversion of an existing tanker. Such arrangements have worked well, but there is a continuing need for a substantial reduction in installation costs in order to improve the economics of marginal field production, and in order to make extended well testing more economically feasible.
Tanker conversions used hitherto have required extensive conversion. In some cases a turret mooring is used which includes a rotary oil flowline joint, and this requires major structural work on the tanker in addition to the complex mooring turret. In other cases, a flexible riser to the tanker has been used but has required large quick connect-disconnect (QCDC) valves with a physical size and weight requiring installation outboard of the tanker bow on a specially installed and relatively large structure.